HYANNIS — Town officials worked on repairing a sinkhole Wednesday night in a parking lot behind 420 Main St.

Initially the hole was 4 feet in diameter, but crews used a jackhammer to knock out the unsupported pavement to make filling it easier, said P.J. Kelliher of the highway department. The hole was about 10 feet deep and between 12-14 feet in diameter just after 9 p.m.

The cause was most likely water from a nearby drainage pipe that slowly compacted the sand underneath the pavement over time, said Will Kadunc of the department of public works. "We get a lot in the spring," he said, "but none this big."

Even when it was just the size of a deep pothole, the sinkhole was still dangerous, Kelliher said. "A bigger vehicle like a truck could fall right in," he said. "You never know where it is," he said of the hole's dimensions.

A gas line was also visible, which had to be shut off, Kelliher said, but there were no signs of a leak.

Crews filled the hole with sand and barricaded the area, he said, and will make a more permanent fix this morning.